This invention relates to a method of producing rows of interlocking elements for slide fasteners. More particularly, the invention is directed to the provision of a row of fastener elements formed from a plastics filament into a multiplicity of discrete interlocking members which are aligned in spaced relationship transversely across and bonded to a plurality of connecting members extending in parallel relationship along a continuous length, the resultant interlocking members being folded along the longitudinal center line of the connecting members into a U-shaped configuration as viewed in end elevation.
There have been heretofore proposed rows of slide fastener elements of the character described, but most of them have relied upon the formation of such elements by extrusion in which a strip of thermoplastic material is extruded piece by piece into a desired shape and bonded with heat to a plurality of parallel connecting members that are fed unidirectionally. Such methods have the drawback that they are rather time-consuming due to limited speeds for extrusion of individual elements and subsequent cooling thereof and hence, the rate of production is considerably retarded.